Biodegradable polymers, the preparation thereof and the use thereof for the production of biodegradable moldings

ABSTRACT

Biodegradable polyetheresteramides Q1 with a molecular weight (M n ) in the range from 6000 to 80,000 g/mol, a viscosity number in the range from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of 0.5% by weight polyetheresteramide Q1 at 25° C.), and a melting point in the range from 50° to 200° C., obtained by reacting a1) from 95 to 99.9% by weight polyetheresteramide P1, obtained by reacting a mixture of 
     b1) 20-95 mol % adipic acid or ester-forming derivatives thereof, and 
     5-80 mol % terephthalic acid or ester-forming derivatives thereof, and 
     b2) a mixture of a dihydroxy compound selected from C 2  -C 6  -alkanediols and C 5  -C 10  -cycloalkanediols, 
     b22) a dihydroxy compound which contains ether functionalities and has the formula I 
     
         HO--((CH.sub.2).sub.n --O)).sub.m --H                      I 
    
     where n is 2, 3 or 4 and m is an integer from 2 to 250, and 
     b23) from 0.5 to 80 mol % of an amino-C 2  -C 12  -alkanol or an amino-C 5  -C 10  -cycloalkanol, with or without 
     b24) a diamino-C 1  -C 8  -alkane, and/or 
     b25) a 2,2&#39;-bisoxazoline 
     where the molar ratio of (b1) to (b2) is in the range from 0.4:1 to 1.5:1, and 
     a2) from 0.1 to 5% by weight of a divinyl ether C1.

The present invention relates to biodegradable polyetheresteramides Q1with a molecular weight (M_(n)) in the range from 6000 to 80,000 g/mol,a viscosity number in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide Q1 at 25° C.), and a melting point inthe range from 50° to 200° C., obtainable by reacting a mixtureconsisting essentially of

(a1) from 95 to 99.9% by weight polyetheresteramide P1 with a molecularweight (M_(n)) in the range from 5000 to 80,000 g/mol, a viscositynumber in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide P1 at 25° C.) and a melting point inthe range from 50° to 200° C., obtainable by reacting a mixtureconsisting essentially of

(b1) a mixture consisting essentially of

20-95 mol % adipic acid or ester-forming derivatives thereof or mixturesthereof,

5-80 mol % terephthalic acid or ester-forming derivatives thereof ormixtures thereof, and

0-5 mol % of a compound containing sulfonate groups, where the total ofthe individual mole percentages is 100 mol %, and

(b2) a mixture of dihydroxy compounds consisting essentially of

(b21) from 15 to 99.3 mol % of a dihydroxy compound selected from thegroup consisting of C₂ -C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols,

(b22) from 0.2 to 85 mol % of a dihydroxy compound which contains etherfunctionalities and has the formula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof,

(b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or an amino-C₅-C₁₀ -cycloalkanol and

(b24) from 0 to 50 mol % of a diamino-C₁ -C₈ -alkane,

(b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of the general formulaII ##STR1## where R¹ is a single bond, a (CH₂)_(q) alkylene group withq=2, 3 or 4, or a phenylene group, where the total of the individualmole percentages is 100 mol %,

where the molar ratio of (b1) to (b2) is chosen in the range from 0.4:1to 1.5:1,

(a2)from 0.1 to 5% by weight of a divinyl ether C1 and

(a3)from 0 to 5 mol %, based on component (b1) from the preparation ofP1, of compound D.

The invention furthermore relates to polymers and biodegradablethermoplastic molding compositions as claimed in the dependent claims,processes for the preparation thereof, the use thereof for producingbiodegradable moldings and adhesives, biodegradable moldings, foams andblends with starch obtainable from the polymers and molding compositionsaccording to the invention.

Polymers which are biodegradable, ie. decompose under environmentalinfluences in an appropriate and demonstrable time span have been knownfor some time. This degradation usually takes place by hydrolysis and/oroxidation, but predominantly by the action of microorganisms such asbacteria, yeasts, fungi and algae. Y. Tokiwa and T. Suzuki (Nature, 270,(1977) 76-78) describe the enzymatic degradation of aliphaticpolyesters, for example including polyesters based on succinic acid andaliphatic diols.

EP-A 565,235 describes aliphatic copolyesters containing --NH--C(O)O--!groups (urethane units). The copolyesters of EP-A 565,235 are obtainedby reacting a prepolyester, which is obtained by reacting essentiallysuccinic acid and an aliphatic diol, with a diisocyanate, preferablyhexamethylene diisocyanate. The reaction with the diisocyanate isnecessary according to EP-A 565,235 because the polycondensation aloneresults only in polymers with molecular weights such that they displayunsatisfactory mechanical properties. A crucial disadvantage is the useof succinic acid or ester derivatives thereof to prepare thecopolyesters because succinic acid and derivatives thereof are costlyand are not available in adequate quantity on the market. In addition,the polyesters prepared using succinic acid as the only acid componentare degraded only extremely slowly.

A chain extension can, according to EP-A 534,295, also advantageously beachieved by reaction with divinyl ethers.

WO 92/13020 discloses copolyether esters based on predominantly aromaticdicarboxylic acids, short-chain ether diol segments such as diethyleneglycol, long-chain polyalkylene glycols such as polyethylene glycol(PEG) and aliphatic diols, where at least 85 mol % of the polyester diolresidue comprise a terephthalic acid residue. The hydrophilicity of thecopolyester can be increased and the crystallinity can be reduced bymodifications such as incorporation of up to 2.5 mol % of metal salts of5-sulfoisophthalic acid. This is said in WO 92/13020 to make thecopolyesters biodegradable. However, a disadvantage of thesecopolyesters is that biodegradation by microorganisms was notdemonstrated, on the contrary only the behavior towards hydrolysis inboiling water was carried out.

According to the statements of Y. Tokiwa and T. Suzuki (Nature, 270(1977) 76-78 or J. of Appl. Polymer Science, 26 (1981) 441-448), it maybe assumed that polyesters which are essentially composed of aromaticdicarboxylic acid units and aliphatic diols, such as PET (polyethyleneterephthalate) and PBT (polybutylene terephthalate), are notenzymatically degradable. This also applies to copolyesters andcopolyether esters which contain blocks composed of aromaticdicarboxylic acid units and aliphatic diols or ether diols.

Furthermore, Y. Tokiwa, T. Suzuki and T. Ando (J. of Appl. Polym. Sci.Vol. 24 (1979) 1701-1711) prepared polyesteramides and blends ofpolycaprolactone and various aliphatic polyamides such as polyamide-6,polyamide-66, polyamide-11, polyamide-12 and polyamide-69 by meltcondensation and investigated them for their biodegradability bylipases. It was found that the biodegradability of such polyesteramidesdepends greatly on whether there is a predominantly random distributionof the amide segments or, for example, a block structure. In general,amide segments tend to reduce the rate of biodegradation by lipases.

However, the crucial factor is that no lengthy amide blocks are present,because it is known from Plant Cell Physiol. 7 (1966) 93, J. Biochem. 59(1966) 537 and Agric. Biol. Chem. 39 (1975) 1219 that the usualaliphatic and aromatic polyamides are biodegradable at the most onlywhen oligomers, otherwise not.

Witt et al. (Handout for a poster at the International Workshop of theRoyal Institute of Technology, Stockholm, Sweden, Apr. 21-23, 1994)describe biodegradable copolyesters based on 1,3-propanediol,terephthalic ester and adipic or sebacic acid. A disadvantage of thesecopolyesters is that moldings produced therefrom, especially sheets,have inadequate mechanical properties.

It is an object of the present invention to provide polymers which aredegradable biologically, ie. by microorganisms, and which do not havethese disadvantages. The intention was, in particular, that the polymersaccording to the invention be preparable from known and low-cost monomerunits and be insoluble in water. It was furthermore the intention thatit be possible to obtain products tailored for the desired usesaccording to the invention by specific modifications such as chainextension, incorporation of hydrophilic groups and groups having abranching action. The aim was moreover that the biodegradation bymicroorganisms should not be achieved at the expense of the mechanicalproperties in order not to restrict the number of applications.

We have found that this object is achieved by the polymers andthermoplastic molding compositions defined at the outset.

We have furthermore found processes for the preparation thereof, the usethereof for producing biodegradable moldings and adhesives, andbiodegradable moldings, foams, blends with starch and adhesivesobtainable from the polymers and molding compositions according to theinvention.

The biodegradable polyetheresteramides Q1 according to the inventionhave a molecular weight (M_(n)) in the range from 6000 to 80,000,preferably from 8000 to 50,000, particularly preferably from 10,000 to40,000 g/mol, a viscosity number in the range from 30 to 450, preferablyfrom 50 to 400 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratioby weight) at a concentration of 0.5% by weight of polyetheresteramideQ1 at 25° C.), and a melting point in the range from 50° to 200° C.,preferably from 60° to 180° C.

The polyetheresteramides Q1 are obtained according to the invention byreacting a mixture consisting essentially of (a1) from 95 to 99.9,preferably from 96 to 99.8, particularly preferably from 97 to 99.65, %by weight of polyetheresteramide P1,

(a2) from 0.1 to 5, preferably from 0.2 to 4, particularly preferablyfrom 0.35 to 3, % by weight of a divinyl ether C1 and

(a3) from 0 to 5, preferably from 0 to 4, mol %, based on component (b1)from the preparation of P1, of compound D.

Preferred polyetheresteramides P1 have a molecular weight (M_(n)) in therange from 5000 to 80,000, preferably from 6000 to 45,000, particularlypreferably from 8000 to 35,000 g/mol, a viscosity number in the rangefrom 30 to 450, preferably from 50 to 400 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polyetheresteramide P1 at 25° C.) and a melting pointin the range from 50 to 200, preferably from 60° to 180° C. Thepolyetheresteramides P1 are, as a rule, obtained by reacting a mixtureconsisting essentially of

(b1) a mixture consisting essentially of

20-95, preferably from 30 to 80, particularly preferably from 40 to 70,mol % of adipic acid or ester-forming derivatives thereof or mixturesthereof,

5-80, preferably from 20 to 70, particularly preferably from 30 to 60,mol % of terephthalic acid or ester-forming derivatives thereof ormixtures thereof, and

0-5, preferably from 0 to 3, particularly preferably from 0.1 to 2, mol% of a compound which contains sulfonate groups, where the total of theindividual mole percentages is 100 mol %, and

(b2) a mixture of dihydroxy compounds consisting essentially of

(b21) from 15 to 99.3, preferably from 60 to 99, particularly preferablyfrom 70 to 97.5 mol % of a dihydroxy compound selected from the groupconsisting of C₂ -C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols,

(b22) from 0.2 to 85, preferably from 0.5 to 40, particularly preferablyfrom 0.5 to 30, mol % of a dihydroxy compound containing etherfunctionalities and having formula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4, preferably two or three, particularly preferablytwo, and m is an integer from 2 to 250, preferably from two to 100, ormixtures thereof,

(b23) from 0.5 to 80, preferably from 0.5 to 50, particularly preferablyfrom 1 to 30, mol % of an amino-C₂ -C₁₂ -alkanol or amino-C₅ -C₁₀-cycloalkanol, and

(b24) from 0 to 50, preferably from 0 to 35, particularly preferablyfrom 0.5 to 30, mol % of a diamino-C₁ -C₈ -alkane,

(b25) from 0 to 50, preferably from 0 to 30, particularly preferablyfrom 0.5 to 20, mol % of a 2,2'-bisoxazoline of the general formula II##STR2## where R¹ is a single bond, a (CH₂)_(q) alkylene group with q=2,3 or 4, or a phenylene group, where the total of the individual molepercentages is 100 mol %,

where the molar ratio of (b1) to (b2) is chosen in the range from 0.4:1to 1.5:1, preferably from 0.6:1 to 1.25:1.

The compound containing sulfonate groups which is normally employed isan alkali metal or alkaline earth metal salt of a dicarboxylic acidcontaining sulfonate groups, or the ester-forming derivatives thereof,preferably alkali metal salts of 5-sulfoisophthalic acid or mixturesthereof, particularly preferably the sodium salt.

The dihydroxy compounds (b21) employed according to the invention areselected from the group consisting of C₂ -C₆ -alkanediols and C₅ -C₁₀-cycloalkanediols, such as ethylene glycol, 1,2- and 1,3-propanediol,1,2- and 1,4-butanediol, 1,5-pentanediol or 1,6-hexanediol, inparticular ethylene glycol, 1,3-propanediol and 1,4-butanediol,cyclopentanediol, cyclohexanediol, 1,2-cyclohexanedimethanol,1,4-cyclohexanedimethanol, particularly preferably ethylene glycol and1,4-butanediol, and mixtures thereof.

The dihydroxy compounds (b22) which are preferably employed arediethylene glycol, triethylene glycol, polyethylene glycol,polypropylene glycol and polytetrahydrofuran (poly-THF), also mixturesthereof or compounds which have different n's (see formula I), forexample polyethylene glycol which contains propylene units (n=3) forexample obtainable by polymerization by conventional methods ofinitially ethylene oxide and subsequently with propylene oxide. Themolecular weight (M_(n)) is usually chosen in the range from 250 to8000, preferably from 600 to 3000, g/mol.

The amino-C₂ -C₁₂ -alkanol or amino-C₅ -C₁₀ -cycloalkanol (componentb23), this being intended also to include4-aminomethylcyclo-hexanemethanol, which is preferably employed is anamino-C₂ -C₆ -alkanol such as 2-aminoethanol, 3-aminopropanol,4-aminobutanol, 5-aminopentanol, 6-aminohexanol, or amino-C₅ -C₆-cycloalkanols such as aminocyclopentanol and aminocyclohexanol ormixtures thereof.

The diamino-C₁ -C₈ -alkane (b24) which is preferably employed is adiamino-C₄ -C₆ -alkane such as 1,4-diaminobutane, 1,5-diaminopentane and1,6-diaminohexane (hexamethylenediamine, HMD).

The compounds of the general formula II (component b25) are, as a rule,obtainable by the process of Angew. Chem. Int. Edit. 11 (1972) 287-288.

From 0 to 5, preferably from 0.01 to 4 mol %, particularly preferablyfrom 0.05 to 4, mol %, based on component (a1), of at least one compoundD with at least three groups capable of ester formation are usedaccording to the invention.

The compounds D preferably contain three to ten functional groupscapable of forming ester linkages. Particularly preferred compounds Dhave three to six functional groups of this type in the molecule, inparticular three to six hydroxyl groups and/or carboxyl groups. Exampleswhich may be mentioned are:

tartaric acid, citric acid, malic acid;

trimethylolpropane, trimethylolethane;

pentaerythritol;

polyethertriols;

glycerol;

trimesic acid;

trimellitic acid or anhydride;

pyromellitic acid or dianhydride and

hydroxyisophthalic acid.

When compounds D which have a boiling point below 200° C. are used inthe preparation of the polyesters P1, a proportion may distil out of thepolycondensation mixture before the reaction. It is therefore preferredto add these compounds in an early stage of the process, such as thetransesterification or esterification stage, in order to avoid thiscomplication and in order to achieve the maximum possible uniformity oftheir distribution within the polycondensate.

In the case of compounds D which boil above 200° C., they can also beemployed in a later stage of the process.

By adding the compound D it is possible, for example, to alter the meltviscosity in a desired manner, to increase the impact strength and toreduce the crystallinity of the polymers or molding compositionsaccording to the invention.

The preparation of the biodegradable polyetheresteramides P1 is known inprinciple (Sorensen and Campbell, Preparative Methods of PolymerChemistry, Interscience Publishers, Inc., New York, 1961, pages 111-127;Encycl. of Polym. Science and Eng., Vol. 12, 2nd Ed., John Wiley & Sons,1988, pages 1-75, in particular pages 59 and 60; Kunststoff-Handbuch,Volume 3/1, Carl Hanser Verlag, Munich, 1992, pages 15-23 (preparationof polyesteramides); WO 92/13019; EP-A 568,593; EP-A 565,235; EP-A28.687 (preparation of polyesters); GB 818,157; GB 1,010,916; GB1,115,512), so that details on this are superfluous.

Thus, for example, the reaction of dimethyl esters of component (b1)with component (b2) can be carried out at from 160° to 230° C. in themelt under atmospheric pressure, advantageously under an inert gasatmosphere.

In a preferred embodiment, first the required amino hydroxy compound(b23) is reacted with component (b1), preferably terephthalic acid,dimethyl terephthalate, adipic acid, di-C₂ -C₆ -alkyl adipate, succinicanhydride, phthalic anhydride, in a molar ratio of 2:1.

In another preferred embodiment, the required diamine compound (b24) isreacted with component (b1), preferably terephthalic acid, dimethylterephthalate, adipic acid, di-C₂ -C₆ -alkyl adipate, succinicanhydride, phthalic anhydride, in a molar ratio of at least 0.5:1,preferably 0.5:1.

In another preferred embodiment, the required bisoxazoline compound(b25) is reacted with component (b1), preferably terephthalic acid,dimethyl terephthalate, adipic acid, di-C₂ -C₄ -alkyl adipate, succinicanhydride, phthalic anhydride, in a molar ratio of at least 0.5:1,preferably 0.5:1.

In the preparation of the biodegradable polyetheresteramide P1 it isadvantageous to use a molar excess of component (b2) relative tocomponent (b1), for example up to 21/2 times, preferably up to 1.67times.

The biodegradable polyetheresteramide P1 is normally prepared withaddition of suitable conventional catalysts (Encycl. of Polym. Scienceand Eng., Vol. 12, 2nd Ed., John Wiley & Sons, 1988, pages 1-75, inparticular pages 59-60; GB 818,157; GB 1,010,916; GB 1,115,512), forexample metal compounds based on the following elements such as Ti, Ge,Zn, Fe, Mn, Co, Zr, V, Ir, La, Ce, Li and Ca, preferably organometalliccompounds based on these metals, such as salts of organic acids,alkoxides, acetylacetonates and the like, particularly preferably basedon lithium, zinc, tin and titanium.

When dicarboxylic acids or anhydrides thereof are used as component(b1), esterification thereof with component (b2) can take place before,at the same time as or after the transesterification. For example, theprocess described in DE-A 23 26 026 for preparing modified polyalkyleneterephthalates can be used.

After the reaction of components (b1) and (b2), the polycondensation iscarried out as far as the desired molecular weight, as a rule underreduced pressure or in a stream of inert gas, for example of nitrogen,with further heating to from 180° to 260° C.

In order to prevent unwanted degradation and/or side reactions, it isalso possible in this stage of the process if required to addstabilizers (see EP-A 21 042 and U.S. Pat. No. 4,321,341). Examples ofsuch stabilizers are the phosphorus compounds described in EP-A 13 461,U.S. Pat. No. 4,328,049 or in B. Fortunato et al., Polymer Vol. 35, No.18, pages 4006-4010, 1994, Butterworth-Heinemann Ltd. These may also insome cases act as inactivators of the catalysts described above.Examples which may be mentioned are: organophosphites, phosphonous acidand phosphorous acid. Examples of compounds which act only asstabilizers are: trialkyl phosphites, triphenyl phosphite, trialkylphosphates, triphenyl phosphate and tocopherol (obtainable as Uvinul®2003AO (BASF) for example).

On use of the biodegradable copolymers according to the invention, forexample in the packaging sector, eg. for foodstuffs, it is as a ruledesirable to select the lowest possible content of catalyst employed andnot to employ any toxic compounds. In contrast to other heavy metalssuch as lead, tin, antimony, cadmium, chromium, etc., titanium and zinccompounds are non-toxic as a rule (Sax Toxic Substance Data Book, ShizuoFujiyama, Maruzen, K. K., 360 S. (cited in EP-A 565,235), see also RomppChemie Lexikon Vol. 6, Thieme Verlag, Stuttgart, N.Y., 9th Edition,1992, pages 4626-4633 and 5136-5143). Examples which may be mentionedare: dibutoxydiacetoacetoxytitanium, tetrabutyl orthotitanate andzinc(II) acetate.

The ratio by weight of catalyst to biodegradable polyetheresteramide P1is normally in the range from 0.01:100 to 3:100, preferably from0.05:100 to 2:100, it also being possible to employ smaller quantities,such as 0.0001:100, in the case of highly active titanium compounds.

The catalyst can be employed right at the start of the reaction,directly shortly before the removal of the excess diol or, if required,also distributed in a plurality of portions during the preparation ofthe biodegradable polyetheresteramides P1. It is also possible ifrequired to employ different catalysts or mixtures thereof.

According to observations to date, all conventional and commerciallyobtainable divinyl ethers can be employed as divinyl ethers C1. Divinylethers selected from the group consisting of 1,4-butanediol divinylether, 1,6-hexanediol divinyl ether and 1,4-cyclohexanedimethanoldivinyl ether are preferably employed.

The preferably cation-catalyzed reaction of the polyetheresteramide P1with the divinyl ether C1 preferably takes place in the melt, it beingnecessary to take care that, where possible, no side reactions which maylead to crosslinking or gel formation occur.

In a particular embodiment, the reaction is normally carried out at from90 to 230, preferably from 100° to 200° C., and the divinyl ether isadvantageously added in several portions or continuously.

If required, the reaction of the polyetheresteramides P1 with thedivinyl ether C1 can also be carried out in the presence of conventionalinert solvents such as toluene, methyl ethyl ketone, tetrahydrofuran(THF) or ethyl acetate or mixtures thereof, in which case the reactionis, as a rule, carried out in the range from 80 to 200, preferably from90° to 150° C.

The reaction with the divinyl ether C1 can be carried out batchwise orcontinuously, for example in stirred vessels, reaction extruders orthrough mixing heads.

It is also possible to employ in the reaction of thepolyetheresteramides P1 with the divinyl ethers C1 conventionalcatalysts which are disclosed in the prior art (for example thosedescribed in EP-A 534,295) or which can be or have been used in thepreparation of the polyetheresteramides P1 and Q2 and, if thepolyetheresteramides P1 have not been isolated in the preparation of thepolyetheresteramides Q1, can now be used further. Examples which may bementioned are: organic carboxylic acids such as oxalic acid, tartaricacid and citric acid, it preferably being necessary to take care that,if possible, no toxic compounds are employed.

Although the theoretical optimum for the reaction of P1 with divinylethers C1 is a 1:1 molar ratio of vinyl ether function to P1 end group(polyetheresteramides P1 with mainly hydroxyl end groups are preferred),the reaction can also be carried out without technical problems at molarratios of from 1:3 to 1.5:1. With molar ratios of >1:1 it is possible ifdesired to add, during the reaction or else after the reaction, a chainextender selected from the components (b2), preferably a C₂ -C₆ -diol.

The biodegradable polymers T1 according to the invention have amolecular weight (M_(n)) in the range from 8000 to 80,000, preferablyfrom 8000 to 50,000, particularly preferably from 10,000 to 40,000g/mol, a viscosity number in the range from 30 to 450, preferably from50 to 400 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer T1 at 25° C.)and a melting point in the range from 50 to 255, preferably from 60° to255° C.

The biodegradable polymers T1 are obtained according to the invention byreacting a polyetheresteramide Q2 with

(d1) 0.1-5, preferably from 0.2 to 4, particularly preferably from 0.3to 3% by weight, based on the polyetheresteramide Q2, of divinyl etherC1 and with

(d2) 0-5, preferably from 0 to 4 mol %, based on component (b1) from thepreparation of polyetheresteramide Q2 via polyetheresteramide P1, ofcompound D.

This normally results in a chain extension, and the resulting polymerchains preferably have a block structure.

Preferred biodegradable polyetheresteramides Q2 have a molecular weight(M_(n)) in the range from 5000 to 80,000, preferably from 6000 to50,000, particularly preferably from 8000 to 40,000, a viscosity numberin the range from 30 to 450, preferably from 50 to 400 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight of polyetheresteramide Q2 at 25° C.), and a melting pointin the range from 50 to 255, preferably from 60° to 255° C.

The polyetheresteramides Q2 are generally obtained by reacting a mixtureconsisting essentially of

(c1) polyetheresteramide P1,

(c2) 0.01-50, preferably from 0.1 to 40, % by weight, based on (c1), ofamino carboxylic acid B1,

where the amino carboxylic acid B1 is selected from the group consistingof the natural amino acids, polyamides with a molecular weight notexceeding 18,000 g/mol, preferably not exceeding 15,000 g/mol, andcompounds which are defined by the formulae IIa or IIb ##STR3## where pis an integer from 1 to 1500, preferably from 1 to 1000, and r is 1, 2,3 or 4, preferably 1 and 2, and G is a radical selected from the groupconsisting of phenylene, --(CH₂)_(n) --, where n is an integer from 1 to12, preferably 1, 5 or 12, --C(R²)H-- and --C(R²)HCH₂, where R² ismethyl or ethyl, and polyoxazolines of the general formula III ##STR4##where R³ is hydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or is tetrahydrofuryl,

and

(c3) 0-5, preferably from 0 to 4, mol %, based on component (b1) fromthe preparation of P1, of compound D.

The natural amino acids which are preferably employed are the following:glycine, aspartic acid, glutamic acid, alanine, valine, leucine,isoleucine, tryptophan, phenylalanine and oligo- and polymers obtainabletherefrom, such as polyaspartimides and polyglutamimides, particularlypreferably glycine.

The polyamides employed are those obtainable by polycondensation of adicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10carbon atoms, such as tetramethylenediamine, pentamethylenediamine,hexamethylenediamine, heptamethylenediamine, octamethylenediamine,nonamethylenediamine and decamethylene-diamine.

Preferred polyamides are polyamide-46, polyamide-66 and polyamide-610.These polyamides are generally prepared by conventional methods. It isself-evident that these polyamides can contain conventional additivesand auxiliaries and that these polyamides can be prepared by usingappropriate regulators.

The polyoxazolines III are, as a rule, prepared by the process describedin DE-A 1,206,585.

Particularly preferred compounds defined by the formulae IIa or IIb are:6-aminohexanoic acid, caprolactam, laurolactam and the oligomers andpolymers thereof with a molecular weight not exceeding 18,000 g/mol.

The reaction of the polyetheresters P1 with the amino carboxylic acidB1, if required in the presence of compound D, preferably takes place inthe melt at from 120° to 260° C. under an inert gas atmosphere, ifdesired also under reduced pressure. The procedure can be both batchwiseand continuous, for example in stirred vessels or (reaction) extruders.

The reaction rate can, if required, be increased by adding conventionaltransesterification catalysts (see those described hereinbefore for thepreparation of the polyetheresteramides P1).

When components B1 with higher molecular weights, for example with a pabove 10 (ten) are used, it is possible to obtain, by reaction with thepolyetheresteramides P1 in stirred vessels or extruders, the desiredblock structures by the choice of the reaction conditions such astemperature, holdup time, addition of transesterification catalysts suchas the abovementioned. Thus, J. of Appl. Polym. Sci., 32 (1986)6191-6207 and Makromol. Chemie, 136 (1970) 311-313 disclose that in thereaction of polyether esters in the melt it is possible to obtain from ablend by transesterification reactions initially block copolymers andthen random copolymers.

The reaction is normally carried out in a similar way to the preparationof the polyetheresteramides Q1.

The biodegradable polymers T2 according to the invention have amolecular weight (M_(n)) in the range from 8000 to 80,000, preferablyfrom 8000 to 50,000, particularly preferably from 10,000 to 40,000,g/mol, a viscosity number in the range from 30 to 450, preferably from50 to 400, g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer T2 at 25° C.),and a melting point in the range from 50 to 255, preferably from 60° to255° C.

The biodegradable polymers T2 are obtained according to the invention byreacting the polyetheresteramide Q1 with

(e1) 0.01-50, preferably from 0.1 to 40, % by weight, based on thepolyetheresteramide Q1, of amino carboxylic acid B1 and with

(e2) 0-5, preferably from 0 to 4, mol %, based on component (b1) fromthe preparation of polyetheresteramide Q1 via polyetheresteramide P1, ofcompound D,

the process expediently being similar to the reaction ofpolyetheresteramide P1 with amino carboxylic acid B1 to givepolyetheresteramide Q2.

The biodegradable polymers T3 according to the invention have amolecular weight (M_(n)) in the range from 8000 to 80,000, preferablyfrom 8000 to 50,000, particularly preferably from 10,000 to 40,000,g/mol, a viscosity number in the range from 30 to 450, preferably from50 to 400, g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer T3 at 25° C.),and a melting point in the range from 50 to 255, preferably from 60° to255° C.

The biodegradable polymers T3 are obtained according to the invention byreacting (f1) polyetheresteramide P2, or (f2) a mixture consistingessentially of polyetheresteramide P1 and 0.01-50, preferably from 0.1to 40, % by weight, based on polyetheresteramide P1, of amino carboxylicacid B1, or (f3) a mixture consisting essentially ofpolyetheresteramides P1 which differ from one another in compositionwith 0.1-5, preferably from 0.2 to 4, particularly preferably from 0.3to 2.5, % by weight, based on the amount of polyetheresteramidesemployed, of divinyl ether C1 and with 0-5, preferably from 0 to 4, mol%, based on the particular molar quantities of component (b1) employedto prepare the polyetheresteramides (f1) to (f3) employed, of compoundD, the reactions expediently being carried out in a similar way to thepreparation of the polyetheresteramides Q1 from the polyetheresteramidesP1 and the divinyl ethers C1.

Preferred biodegradable polyetheresteramides P2 have a molecular weight(M_(n)) in the range from 5000 to 80,000, preferably from 6000 to45,000, particularly preferably from 10,000 to 40,000, g/mol, aviscosity number in the range from 30 to 450, preferably from 50 to 400,g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight of polyetheresteramide P2 at 25° C.) anda melting point in the range from 50 to 255, preferably from 60° to 255°C.

The biodegradable polyetheresters P2 are obtained as a rule by reactinga mixture consisting essentially of

(g1) a mixture consisting essentially of

20-95, preferably from 25 to 80, particularly preferably from 30 to 70,mol % of adipic acid or ester-forming derivatives thereof or mixturesthereof,

5-80, preferably from 20 to 75, particularly preferably from 30 to 70,mol % of terephthalic acid or ester-forming derivatives thereof ormixtures thereof, and

0-5, preferably from 0 to 3, particularly preferably from 0.1 to 2, mol% of a compound which contains sulfonate groups, where the total of theindividual mole percentages is 100 mol %, and

(g2) mixture (b2),

where the molar ratio of (g1) to (g2) is chosen in the range from 0.4:1to 1.25:1, preferably from 0.6:1 to 1.25:1,

(g3) from 0.01 to 40, preferably from 0.1 to 30, % by weight, based oncomponent (g1), of amino carboxylic acid B1, and

(g4) from 0 to 5, preferably from 0 to 4, particularly preferably from0.01 to 3.5, mol %, based on component (g1), of compound D.

The biodegradable polyetheresteramides P2 are expediently prepared in asimilar way to the preparation of the polyetheresteramides P1, it beingpossible to add the amino carboxylic acid B1 both at the start of thereaction and after the esterification or transesterification stage.

In a preferred embodiment, polyetheresteramides P2 whose repeating unitsare randomly distributed in the molecule are employed.

The biodegradable thermoplastic molding compositions T4 are obtainedaccording to the invention by mixing in a conventional way, preferablywith the addition of conventional additives such as stabilizers,processing aids, fillers etc. (see J. of Appl. Polym. Sc., 32 (1986)6191-6207; WO 92/0441; EP 515,203; Kunststoff-Handbuch, Vol. 3/1, CarlHanser Verlag, Munich, 1992, pages 24-28).

(h1) 99.5-0.5% by weight of polyetheresteramide Q1 with

(h2) 0.5-99.5% by weight of hydroxy carboxylic acid H1 of the generalformula Va or Vb ##STR5## where x is an integer from 1 to 1500,preferably from 1 to 1000, and y is 1, 2, 3 or 4, preferably 1 and 2,and M is a radical selected from the group consisting of phenylene,--(CH₂)_(z) -- where z is an integer from 1, 2, 3, 4 or 5, preferably 1and 5, --C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl.

The hydroxy carboxylic acid H1 employed in a preferred embodiment is:glycolic acid, D-, L- or D,L-lactic acid, 6-hydroxyhexanoic acid, thecyclic derivatives thereof such as glycolide (1,4-di-oxane-2,5-dione),D-, L-dilactide (3,6-dimethyl-1,4-di-oxane-2,5-dione), p-hydroxybenzoicacid and the oligomers and polymers thereof such aspoly-3-hydroxybutyric acid, polyhydroxyvaleric acid, polylactide(obtainable as EcoPLA® (from Cargill) for example) and a mixture ofpoly-3-hydroxybutyric acid and polyhydroxyvaleric acid (the latter isobtainable from Zeneca under the name Biopol®).

In a preferred embodiment, high molecular weight hydroxy carboxylicacids H1 such as polycaprolactone or polylactide or polyglycolide with amolecular weight (M_(n)) in the range from 10,000 to 150,000, preferablyfrom 10,000 to 100,000, g/mol are employed.

WO 92/0441 and EP-A 515,203 disclose that high molecular weightpolylactide without added plasticizers is too brittle for mostapplications. It is possible in a preferred embodiment to prepare ablend starting from 0.5-20, preferably from 0.5 to 10, % by weight ofpolyetheresteramide Q1 and 99.5-80, preferably from 99.5 to 90, % byweight of polylactide, which displays a distinct improvement in themechanical properties, for example an increase in the impact strength,compared with pure polylactide.

Another preferred embodiment relates to a blend obtainable by mixingfrom 99.5 to 40, preferably from 99.5 to 60, % by weight ofpolyetheresteramide Q1 and from 0.5 to 60, preferably from 0.5 to 40, %by weight of a higher molecular weight hydroxy carboxylic acid H1,particularly preferably polylactide, polyglycolide,poly-3-hydroxybutyric acid and polycaprolactone. Blends of this type arecompletely biodegradable and, according to observations to date, havevery good mechanical properties.

According to observations to date, the thermoplastic moldingcompositions T4 according to the invention are preferably obtained byobserving short mixing times, for example when carrying out the mixingin an extruder. It is also possible to obtain molding compositions whichhave predominantly blend structures by choice of the mixing parameters,in particular the mixing time and, if required, the use of inactivators,ie. it is possible to control the mixing process so thattransesterification reactions can also take place at least partly.

In another-preferred embodiment it is possible to replace 0-50,preferably 0-30, mol % of the adipic acid or the ester-formingderivatives thereof or the mixtures thereof by at least one otheraliphatic C₄ -C₁₀ - or cycloaliphatic C₅ -C₁₀ -dicarboxylic acid ordimer fatty acid such as succinic acid, glutaric acid, pimelic acid,suberic acid, azelaic acid or sebacic acid or an ester derivate such asthe di-C₁ -C₆ -alkyl esters thereof or the anhydrides thereof such assuccinic anhydride, or mixtures thereof, preferably succinic acid,succinic anhydride, sebacic acid, dimer fatty acid and di-C₁ -C₆ -alkylesters such as dimethyl, diethyl, di-n-propyl, diisobutyl, di-n-pentyl,dineopentyl, di-n-hexyl esters thereof, especially dimethyl succinate.

A particularly preferred embodiment relates to the use as component (b1)of the mixture, described in EP-A 7445, of succinic acid, adipic acidand glutaric acid and the C₁ -C₆ -alkyl esters thereof such as dimethyl,diethyl, di-n-propyl, diisobutyl, di-n-pentyl, dineopentyl, di-n-hexylesters, especially the dimethyl esters thereof.

In another preferred embodiment it is possible to replace 0-50,preferably 0-40, mol % of the terephthalic acid or the ester-formingderivatives thereof, or the mixtures thereof, by at least one otheraromatic dicarboxylic acid such as isophthalic acid, phthalic acid or2,6-naphthalenedicarboxylic acid, preferably isophthalic acid, or anester derivative such as a di-C₁ -C₆ -alkyl ester such as dimethyl,diethyl, di-n-propyl, diisobutyl, di-n-pentyl, dineopentyl, di-n-hexylester, in particular a dimethyl ester, or mixtures thereof.

It should be noted in general that the various polymers according to theinvention can be worked up in a conventional way by isolating thepolymers or, in particular if it is wished to react thepolyetheresteramides P1, P2, Q2 and Q1 further, by not isolating thepolymers but immediately processing them further.

The polymers according to the invention can be applied to coatingsubstrates by rolling, spreading, spraying or pouring. Preferred coatingsubstrates are those which are compostable or rot such as moldings ofpaper, cellulose or starch.

The polymers according to the invention can also be used to producemoldings which are compostable. Moldings which may be mentioned by wayof example are: disposable articles such as crockery, cutlery, refusesacks, sheets for agriculture to advance harvesting, packaging sheetsand vessels for growing plants.

It is furthermore possible to spin the polymers according to theinvention into threads in a conventional way. The threads can, ifrequired, be stretched, stretch-twisted, stretch-wound, stretch-warped,stretch-sized and stretch-texturized by customary methods. Thestretching to flat yarn can moreover take place in the same working step(fully drawn yarn or fully oriented yarn) or in a separate step. Thestretch warping, stretch sizing and stretch texturizing are generallycarried out in a working step separate from the spinning. The threadscan be further processed to fibers in a conventional way. Sheet-likestructures can then be obtained from the fibers by weaving or knitting.

The moldings, coating compositions and threads etc. described above can,if required, also contain fillers which can be incorporated during thepolymerization process at any stage or subsequently, for example in amelt of the polymers according to the invention.

It is possible to add from 0 to 80 % by weight of fillers, based on thepolymers according to the invention. Examples of suitable fillers arecarbon black, starch, lignin powder, cellulose fibers, natural fiberssuch as sisal and hemp, iron oxides, clay minerals, ores, calciumcarbonate, calcium sulfate, barium sulfate and titanium dioxide. Thefillers can in some cases also contain stabilizers such as tocopherol(vitamin E), organic phosphorus compounds, mono-, di- and polyphenols,hydroquinones, diarylamines, thioethers, UV stabilizers, nucleatingagents such as talc, and lubricants and mold release agents based onhydrocarbons, fatty alcohols, higher carboxylic acids, metal salts ofhigher carboxylic acids such as calcium and zinc stearate, and montanwaxes. Such stabilizers etc. are described in detail inKunststoff-Handbuch, Vol. 3/1, Carl Hanser Verlag, Munich, 1992, pages24-28.

The polymers according to the invention can additionally be colored inany desired way by adding organic or inorganic dyes. The dyes can alsoin the widest sense be regarded as filler.

A particular application of the polymers according to the inventionrelates to the use as compostable sheet or a compostable coating asouter layer of diapers. The outer layer of the diapers effectivelyprevents penetration by liquids which are absorbed inside the diaper bythe fluff and superabsorbers, preferably by biodegradablesuperabsorbers, for example based on crosslinked polyacrylic acid orcrosslinked polyacrylamide. It is possible to use a web of a cellulosematerial as inner layer of the diaper. The outer layer of the describeddiapers is biodegradable and thus compostable. It disintegrates oncomposting so that the entire diaper rots, whereas diapers provided withan outer layer of, for example, polyethylene cannot be composted withoutprevious reduction in size or elaborate removal of the polyethylenesheet.

Another preferred use of the polymers and molding compositions accordingto the invention relates to the production of adhesives in aconventional way (see, for example, Encycl. of Polym. Sc. and Eng. Vol.1, "Adhesive Compositions", pages 547-577). The polymers and moldingcompositions according to the invention can also be processed asdisclosed in EP-A 21042 using suitable tackifying thermoplastic resins,preferably natural resins, by the methods described therein. Thepolymers and molding compositions according to the invention can also befurther processed as disclosed in DE-A 4 234 305 to solvent-freeadhesive systems such as hot melt sheets.

Another preferred application relates to the production of completelydegradable blends with starch mixtures (preferably with thermoplasticstarch as described in WO 90/05161) in a similar process to thatdescribed in DE-A 42 37 535. The polymers and thermoplastic moldingcompositions according to the invention can, according to observationsto date, because of their hydrophobic nature, their mechanicalproperties, their complete biodegradability, their good compatibilitywith thermoplastic starch and not least because of their favorable rawmaterial basis, advantageously be employed as synthetic blend component.

Further applications relate, for example, to the use of the polymersaccording to the invention in agricultural mulch, packaging material forseeds and nutrients, substrate in adhesive sheets, baby pants, pouches,bed sheets, bottles, boxes, dust bags, labels, cushion coverings,protective clothing, hygiene articles, handkerchiefs, toys and wipes.

Another use of the polymers and molding compositions according to theinvention relates to the production of foams, generally by conventionalmethods (see EP-A 372 846; Handbook of Polymeric foams and FoamTechnology, Hanser Publisher, Munich, 1991, pages 375-408). Thisnormally entails the polymer or molding composition according to theinvention being initially melted, if required with the addition of up to5 % by weight of compound D, preferably pyromellitic dianhydride andtrimellitic anhydride, then a blowing agent being added and theresulting mixture being exposed to reduced pressure by extrusion,resulting in foaming.

The advantages of the polymers according to the invention over knownbiodegradable polymers are a favorable raw material basis with readilyavailable starting materials such as adipic acid, terephthalic acid andconventional diols, interesting mechanical properties due to thecombination of "hard" (owing to the aromatic dicarboxylic acids such asterephthalic acid) and "soft" (owing to the aliphatic dicarboxylic acidssuch as adipic acid) segments in the polymer chain and the variation inuses due to simple modifications, a satisfactory degradation bymicroorganisms, especially in compost and soil, and a certain resistanceto microorganisms in aqueous systems at room temperature, which isparticularly advantageous for many applications. The randomincorporation of the aromatic dicarboxylic acids of component (b1) invarious polymers makes the biological attack possible and thus achievesthe desired biodegradability.

A particular advantage of the polymers according to the invention isthat it is possible by tailoring the formulations to optimize both thebiodegradation and the mechanical properties for the particularapplication.

It is furthermore possible depending on the preparation processadvantageously to obtain polymers with predominantly random distributionof monomer units, polymers with predominantly block structures andpolymers with predominantly blend structure or blends.

EXAMPLES

Abbreviations

TTB: Titanium tetrabutoxide

DMT: Dimethyl terephthalate

Preparation of a polyetheresteramide Q1_(a)

Precursor 1

4.672 kg of 1,4-butanediol, 7.000 kg of adipic acid and 50 g of tindioctoate were heated under inert gas (nitrogen) to 230°-240° C. Aftermost of the water formed in the reaction had distilled out, 10 g of TTBwere added. As soon as the acid number AN had fallen below 1, the excessbutanediol was distilled out under reduced pressure until the OH numberreached about 56.

Precursor 2

58.5 g of DMT were heated with 36.5 g of ethanolamine while stirringslowly under a nitrogen atmosphere to 180° C. After 30 min, 360 g ofprecursor 1, 175 g of DMT, 0.65 g of pyromellitic dianhydride, 300 g of1,4-butanediol, 63.5 g of diethylene glycol and 1 g of TTB were addedunder a nitrogen atmosphere. The methanol and water formed during thetransesterification were removed by distillation. The mixture was heatedto 230° C. over the course of 3 h while increasing the stirring speedand, after 2 h, 0.4 g of 50% strength aqueous phosphorous acid wasadded. Over the course of 2 h, the pressure was reduced to 5 mbar andwas then kept below 2 mbar and at 240° C. for 45 min, during which theexcess 1,4-butanediol distilled out. An elastic, pale brown product wasobtained.

OH number: 16 mg KOH/g

AN: below 1 mg KOH/g

prim. amine: below 0.1 g/100 g.

DSC measurements revealed that precursor 2 had two melting points at 63°C. and 82° C. and a glass transition temperature of -36° C.

Q1_(a)

200 g of the precursor 2 were cooled to 170° C., and 4.2 g of1,4-butanediol divinyl ether were added in 4 portions over the course of45 min, which led to a distinct increase in the melt viscosity. Thispoints to the increase in molecular weight.

OH number: 4 mg KOH/g

AN: below 1 mg KOH/g.

Preparation of biodegradable polymer T1_(a)

384 g of 1,4-butanediol, 6.1 g of ethanolamine, 316 g of DMT and 1 g ofTTB were heated while stirring slowly under a nitrogen atmosphere to180° C. The methanol formed in the transesterification was distilledout. After adding 101.6 g of adipic acid and 278 g of polyethyleneglycol with a molecular weight of 600 g/mol, the mixture was heated to230° C. under a nitrogen atmosphere while increasing the stirring speedto over the course of 2 h, and the water formed in the condensation wasdistilled out. Then 62.5 g of a non-extracted, monomer-containingpolyamide with a viscosity number of 68 and about 10.5% by weight ofresidual extract (eg. Ultramid® B15 from BASF) were added under anitrogen atmosphere. After 2 h, 0.4 g of 50% strength aqueousphosphorous acid was added, the pressure was reduced stepwise to 5 mbarand then kept below 2 mbar and at 230° C. for 45 min, during which thewater formed in the condensation and the excess 1,4-butanediol distilledout.

OH number: 19 mg KOH/g

AN: below 1 mg KOH/g.

DSC measurements revealed two melting points at 124° and 216° C. and aglass transition temperature -44° C.

200 g of this product were cooled to 170° C., and 4.95 g of1,4-butanediol divinyl ether were added in 4 portions over the course of45 min. The increase in molecular weight was detectable from thedistinct increase in melt viscosity.

OH number: 6 mg KOH/g

AN: below 1 mg KOH/g

Enzyme assay with Rhizopus arrhizus: ΔDOC: 82 mg/l/ΔDOC (PCL): 2455.

Methods of measurement

Enzyme assay

The polymers were cooled with liquid nitrogen or dry ice in a mill andfinely ground (the rate of enzymatic breakdown increases with thesurface area of the milled material). The enzyme assay was carried outby placing 30 mg of finely ground polymer powder and 2 ml of a 20 mmol/laqueous K₂ HPO₄ /KH₂ PO₄ buffer solution (pH: 7.0) in an Eppendorf tube(2 ml) and equilibrated on a rotator at 37° C. for 3 h. Subsequently 100units of lipase from either Rhizopus arrhizus, Rhizopus delemar orPseudomonas pl. were added and incubated on the rotator (250 rpm) at 37°C. for 16 h. The reaction mixture was then filtered through a Millipore®membrane (0.45 μm), and the DOC (dissolved organic carbon) of thefiltrate was measured. Similar DOC measurements were carried out in onecase only with buffer and enzyme (as enzyme control) and in one caseonly with buffer and sample (as blank).

The ΔDOC values found (DOC (sample+enzyme)-DOC (enzyme control)-DOC(blank value)) can be regarded as a measure of the enzymaticdegradability of the samples. They are presented in each case comparingwith a measurement with powder from polycaprolactone® Tone P 787 (UnionCarbide). It must be remembered in the assessment that these are notabsolutely quantifiable data. The connection between the surface area ofthe milled material and the speed of enzymatic breakdown has beenreferred to above. Furthermore the enzyme activities may also vary.

The hydroxyl number (OH number) and acid number (AN) were determined bythe following methods:

(a) Determination of the apparent hydroxyl number

10 ml of toluene and 9.8 ml of acetylating reagent (see below) wereadded to about 1 to 2 g of accurately weighed test substance and heatedat 95° C. with stirring for 1 h. Then 5 ml of distilled water wereadded. After cooling to room temperature, 50 ml of tetrahydrofuran (THF)were added, and potentiographic titration to the turning point wascarried out with standard ethanolic KOH solution.

The experiment was repeated without test substance (blank sample).

The apparent OH number was then found from the following formula:

The apparent OH number c×t×56.1(V2-V1)/m (in mg KOH/g)

where

c=amount of substance concentration of the standard ethanolic KOHsolution in mol/l

t=titer of the standard ethanolic KOH solution

m=weight of test substance in mg

V1=ml of standard solution used with test substance

V2=ml of standard solution used without test substance.

Reagents used:

standard ethanolic KOH solution, c=0.5 mol/l, titer 0.9933 (Merck, Cat.No. 1.09114) acetic anhydride, analytical grade (Merck, Cat. No. 42)pyridine, analytical grade (Riedel de Haen, Cat. No. 33638) acetic acid,analytical grade (Merck, Cat. No. 1.00063) acetylating reagent: 810 mlof pyridine, 100 ml of acetic anhydride and 9 ml of acetic acid water,deionized THF and toluene

(b) Determination of the acid number (AN) About 1 to 1.5 g of testsubstance were weighed accurately, 10 ml of toluene and 10 ml ofpyridine were added, and the mixture was then heated to 95° C. Afterdissolving, the solution was cooled to room temperature, 5 ml of waterand 50 ml of THF were added, and titration was carried out with 0.1Nstandard ethanolic KOH solution.

The determination was repeated without test substance (blank sample).

The acid number was then found from the following formula:

AN=c×t×56.1(V1-V2)/m (in mg KOH/g)

where

c=amount of substance concentration of the standard ethanolic KOHsolution in mol/l

t=titer of the standard ethanolic KOH solution

m=weight of test substance in mg

V1=ml of standard solution used with test substance

V2=ml of standard solution used without test substance.

Reagents used:

standard ethanolic KOH solution, c=0.1 mol/l, titer=0.9913 (Merck, Cat.No. 9115) pyridine, analytical grade (Riedel de Haen, Cat. No. 33638)water, deionized THF and toluene

(c) Determination of the OH number

The OH number is obtained from the sum of the apparent OH number and theAN:

OH number=apparent OH number+AN

The viscosity number (VN) was measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weight of polymerat 25° C.

The DSC measurements were carried out with a DuPont DSC 912apparatus+thermal analyzer 990. The temperature and enthalpy calibrationtook place in a conventional way. The weight of sample was typically 13mg. The heating and cooling rates were 20K/min. The samples weremeasured under the following conditions: 1. Heating run on samples inthe state supplied, 2. Rapid cooling from the melt, 3. Heating run onthe samples cooled from the melt (samples from 2). The second DSC runsin each case were used to compare various samples after a uniformthermal history.

We claim:
 1. A biodegradable polyetheresteramide Q1 with a molecularweight (M_(n)) in the range from 6000 to 80,000 g/mol, a viscositynumber in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide Q1 at 25° C.), and a melting point inthe range from 50° to 200° C., obtained by reacting a mixture of(a1)from 95 to 99.9% by weight polyetheresteramide P1 with a molecularweight (M_(n)) in the range from 5000 to 80,000 g/mol, a viscositynumber in the range from 30 to 450 g/ml (measured ino-dichlorbenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide P1 at 25° C.) and a melting point inthe range from 50° to 200° C. obtainable by reacting a mixtureconsisting essentially of (b1) a mixture consisting essentially of (b1)20-95 mol % adipic acid or ester-forming derivatives thereof or mixturesthereof, (b12) 5-80 mol % terephthalic acid or ester-forming derivativesthereof or mixtures thereof, and (b13) 0-5 mol % of a compoundcontaining sulfonate groups, where 0-50 mol % of component (b11) can bereplaced by at least one other aliphatic C₄ -C₁₀ - or cycloaliphatic C₅-C₁₀ -dicarboxylic acid or dimer fatty acid, and where 0-50 mol % ofcomponent (b12) can be replaced by another aromatic dicarboxylic acid,and the total of the individual mole percentages is 100 mol %, and (b2)a mixture of dihydroxy compounds composed of (b21) from 15 to 99.3 mol %of a dihydroxy compound selected from the group consisting of C₂ -C₆-alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22) from 0.2 to 85 mol %of a dihydroxy compound which contains ether functionalities and has theformula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof, (b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or anamino-C₅ -C₁₀ -cycloalkanol and (b24) from 0 to 50 mol % of a diamino-C₁-C₈ -alkane, (b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of theformula II ##STR6## where R¹ is a single bond, a (CH₂)_(q) alkylenegroup with q=2, 3 or 4, or a phenylene group, where the total of theindividual mole percentages is 100 mol %,where the molar ratio of (b1)to (b2) is chosen in the range from 0.4:1 to 1.5:1, (a2) from 0.1 to 5%by weight of a divinyl ether C1 and (a3) from 0 to 5 mol %, based oncomponent (b1) from the preparation of P1, of compound D with at leastthree groups capable of ester formation.
 2. A biodegradable polymer T1with a molecular weight (M_(n)) in the range from 8000 to 80,000 g/mol,with a viscosity number in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0-5% by weight of polymer T1 at 25° C.) and a melting point in the rangefrom 50° to 255° C., obtainable by reacting the polyetheresteramide Q2with a molecular weight (M_(n)) in the range from 5000 to 80,000 g/mol,a viscosity number in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide Q2 at 25° C.), and a melting point inthe range from 50° to 255° C., obtained by reacting a mixture consistingessentially of(c1) polyetheresteramide P1 as set forth in claim 1, (c2)0.01-50% by weight, based on (c1), of amino carboxylic acid B1where theamino carboxylic acid B1 is selected from the group consisting of thenatural amino acids, polyamides with a molecular weight not exceeding18,000 g/mol, obtained by polycondensation of a dicarboxylic acid with 4to 6 carbon atoms and a diamine with 4 to 10 carbon atoms and compoundswhich are defined by the formulae IIIa and IIIb ##STR7## where p is aninteger from 1 to 1500 and r is an integer from 1 to 4, and G is aradical which is selected from the group consisting of phenylene,--(CH₂)_(n) -- where n is an integer from 1 to 12, --C(R²)H-- and--C(R²)HCH₂ where R² is methyl or ethyl, and polyoxazolines with therepeating unit IV ##STR8## where R³ is hydrogen, C₁ -C₆ -alkyl, C₅ -C₈-cycloalkyl, phenyl which is unsubstituted or substituted up to threetimes by C₁ -C₄ -alkyl groups, or tetrahydrofuryl, and (c3) 0-5 mol %,based on the molar quantity of component (b1) used to prepare P1, ofcompound D with at least three groups capable of ester formation,with(d1) 0.1-5% by weight, based on the polyetheresteramide Q2, of divinylether C1, and with (d2) 0-5 mol %, based on the molar quantity ofcomponenet (b1) used to prepare polyetheresteramide Q2, of compound D.3. A biodegradable polymer T2 with a molecular weight (M_(n)) in therange from 8000 to 80,000 g/mol, with a viscosity number in the rangefrom 30 to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratioby weight) at a concentration of 0.5% by weight polymer T2 at 25° C.)and a melting point in the range from 50° to 255° C., obtained byreacting the polyetheresteramide Q1 as claimed in claim 1 with(e1)0-01-50% by weight, based on polyetheresteramide Q1, of amino carboxylicacid B1where the amino carboxylic acid B1 is selected from the groupconsisting of the natural amino acids, polyamides with a molecularweight not exceeding 18,000 g/mol, obtained by polycondensation of adicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10carbon atoms and compounds which are defined by the formulae IIIa andIIIb ##STR9## where p is an integer from 1 to 1500 and r is an integerfrom 1 to 4, and G is a radical which is selected from the groupconsisting of phenylene, --(CH₂)_(n) -- where n is an integer from 1 to12, --C(R²)H-- and --C(R²)HCH₂ where R² is methyl or ethyl, andpolyoxazolines with the repeating unit IV ##STR10## where R³ ishydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl, and with (e2) 0-5 mol %, based on the molar quantityof component (b1) used to prepare polyetheresteramide Q1, of compound Dwith at least three groups capable of ester formation.
 4. Abiodegradable polymer T3 with a molecular weight (M_(n)) in the rangefrom 8000 to 80,000 g/mol, with a viscosity number in the range from 30to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight polymer T3 at 25° C.) and amelting point in the range from 50° to 255° C., obtained by reacting(f1)polyetheresteramide P2 with a molecular weight (M_(n)) in the range from5000 to 80,000 g/mol, a viscosity number in the range from 30 to 450g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight polyetheresteramide P2 at 25° C.) and amelting point in the range from 50° to 255° C.,obtained by reacting amixture consisting essentially of (g1) a mixture consisting essentiallyof20-95 mol % adipic acid or ester-forming derivatives thereof ormixtures thereof, 5-80 mol % terephthalic acid or ester-formingderivatives thereof or mixtures thereof, and 0-5 mol % of a compoundwhich contains sulfonate groups, p2 where the total of the individualmole percentages is 100 mol %, (g2) mixture (b2) of dihydroxy compoundscomposed of (b21) from 15 to 99.3 mol % of a dihydroxy compound selectedfrom the group consisting of C₂ -C₆ -alkanediols and C₅ -C₁₀-cycloalkanediols, (b22) from 0.2 to 85 mol % of a dihydroxy compoundwhich contains ether functionalities and has the formula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof, (b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or anamino-C₅ -C₁₀ -cycloalkanol and (b24) from 0 to 50 mol % of a diamino-C₁-C₈ -alkane, (b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of theformula II ##STR11## where R¹ is a single bond, a (CH₂)_(q) alkylenegroup with q=2, 3 or 4, or a phenylene group, where the total of theindividual mole percentages is 100 mol %,where the molar ratio of (g1)to (g2) is chosen in the range from 0.4:1 to 1.5:1, (g3) from 0.01 to40% by weight, based on component (g1), of amino carboxylic acidB1,where the amino carboxylic acid B1 is selected from the groupconsisting of the natural amino acids, polyamides with a molecularweight not exceeding 18,000 g/mol, obtained by polycondensation of adicarboxylic acid with 4 to 6 carbon atoms and a diamine with 4 to 10carbon atoms and compounds which are defined by the formulae IIIa andIIIb ##STR12## where p is an integer from 1 to 1500 and r is an integerfrom 1 to 4, and G is a radical which is selected from the groupconsisting of phenylene, --(CH₂)_(n) -- where n is an integer from 1 to12, --C(R²)H-- and --C(R²)HCH₂ where R² is methyl or ethyl, andpolyoxazolines with the repeating unit IV ##STR13## where R³ ishydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl, and (g4) from 0 to 5 mol % based on component (g1),of compound D with at least three groups capable of ester formation,or(f2) a mixture consisting essentially of polyetheresteramide P1 as setforth in claim 1 and 0.01-50% by weight, based on polyetheresteramideP1, of amino carboxylic acid B1, or (f3) a mixture consistingessentially of polyetheresteramides P1 which differ from one another incomposition,with 0.1-5% by weight, based on the amount ofpolyetheresteramides employed, of divinyl ether C1 and with 0-5 mol %,based on the particular molar quantities of component (g1) or ofcomponent (b1) employed to prepare the polyetheresteramides (P2) or themixtures (f2) or (f3) employed, of compound D with at least three groupscapable of ester formation.
 5. A biodegradable thermoplastic moldingcomposition T4 obtained by mixing in a conventional way(h1) 99.5-0.5% byweight polyetheresteramide Q1 as defined in claim 1 with (h2) 0.5-99.5%by weight hydroxycarboxylic acid H1 of the formula Va or Vb ##STR14##where x is an integer from 1 to 1500 and y is an integer from 1 to 4,and M is a radical which is selected from the group consisting ofphenylene, --(CH₂)_(z) --, where z is an integer from 1 to 5, --C(R²)H--and --C(R²)HCH₂ -- where R² is methyl or ethyl.
 6. A compostable moldingobtained from polyetheresters Q1 as defined in claim
 1. 7. An adhesiveobtained from polyetheresteramides Q1 as defined in claim
 1. 8. Abiodegradable blend obtained from a mixture comprisingpolyetheresteramides Q1 as defined in claim 1 and starch.
 9. Abiodegradable foam obtained from polyetheresteramides as defined inclaim
 1. 10. A paper coating composition obtained frompolyetheresteramides Q1 as defined in claim
 1. 11. A process forpreparing the biodegradable polyetheresteramides Q1 with a molecularweight (M_(n)) in the range from 6000 to 80,000 g/mol, a viscositynumber in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide Q1 at 25° C.), and a melting point inthe range from 50° to 200° C., which comprises, in a first steppreparingpolyetheresteramide P1 with a molecular weight (M_(n)) in the range from5000 to 80,000 g/mol, a viscosity number in the range from 30 to 450g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight polyetheresteramide P1 at 25° C.) and amelting point in the range from 50° to 200° C., obtained by reacting amixture consisting essentially of (b1) a mixture consisting essentiallyof (b11) 20-95 mol % adipic acid or ester-forming derivatives thereof ormixtures thereof, (b12) 5-80 mol % terephthalic acid or ester-formingderivatives thereof or mixtures thereof, and (b13) 0-5 mol % of acompound containing sulfonate groups, where 0-50 mol % of component(b11) can be replaced by at least one other aliphatic C₄ -C₁₀ - orcycloaliphatic C₅ -C₁₀ -dicarboxylic acid or dinier fatty acid, andwhere 0-50 mol % of component (b12) can be replaced by another aromaticdicarboxylic acid, the total of the individual mole percentages being100 mol %, and (b2) a mixture of dihydroxy compounds composed of (b21)from 15 to 99.3 mol % of a dihydroxy compound selected from the groupconsisting of C₂ -C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22)from 0.2 to 85 mol % of a dihydroxy compound which contains etherfunctionalities and has the formula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof, (b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or anamino-C₅ -C₁₀ -cycloalkanol and (b24) from 0 to 50 mol % of a diamino-C₁-C₈ -alkane, (b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of thegeneral formula II ##STR15## where R¹ is a single bond, a (CH₂)_(q)alkylene group with q=2, 3 or 4, or a phenylene group, where the totalof the individual mole percentages is 100 mol %,where the molar ratio of(b1) to (b2) is chosen in the range from 0.4:1 to 1.5:1, and in a secondstep reacting a mixture of (a1) from 95 to 94.9% by weightpolyetheresteramide P1 (a2) from 0.1 to 5% by weight divinyl ether C1and (a3) from 0 to 5 mol %, based on the molar quantity of component(b1) used to prepare P1, of compound D with at least three groupscapable of ester formation.
 12. A process for preparing thebiodegradable polymers T1 with a molecular weight (M_(n)) in the rangefrom 8000 to 80,000 g/mol, with a viscosity number in the range from 30to 450 g/ml (measured in o-dichloro-benzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight of polymer T1 at 25° C.)and a melting point in the range from 50° to 255° C., which comprises,in a first step, preparing polyetheresteramide Q2 with a molecularweight (M_(n)) in the range from 5000 to 80,000 g/mol, a viscositynumber in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide Q2 at 25° C.), and a melting point inthe range from 50° to 255° C., obtained by reacting a mixture consistingessentially of(c1) polyetheresteramide P1 with a molecular weight(M_(n)) in the range from 5000 to 80,000 g/mol, a viscosity number inthe range from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weightpolyetheresteramide P1 at 25° C.) and a melting point in the range from50° to 200° C., obtained by reacting a mixture consisting essentially of(b1) a mixture consisting essentially of (b11) 20-95 mol % adipic acidor ester-forming derivatives thereof or mixtures thereof, (b12) 5-80 mol% terephthalic acid or ester-forming derivatives thereof or mixturesthereof, and (b13) 0-5 mol % of a compound containing sulfonate groups,where 0-50 mol % of component (b11) can be replaced by at least oneother aliphatic C₄ -C₁₀ - or cycloaliphatic C₅ -C₁₀ -dicarboxylic acidor dinier fatty acid, and where 0-50 mol % of component (b12) can bereplaced by another aromatic dicarboxylic acid, where the total of theindividual mole percentages being 100 mol %, and (b2) a mixture ofdihydroxy compounds composed of (b21) from 15 to 99.3 mol % of adihydroxy compound selected from the group consisting of C₂ -C₆-alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22) from 0.2 to 85 mol %of a dihydroxy compound which contains ether functionalities and has theformula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof, (b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or anamino-C₅ -C₁₀ -cycloalkanol and (b24) from 0 to 50 mol % of a diamino-C₁-C₈ -alkane, (b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of theformula II ##STR16## where R¹ is a single bond, a (CH₂)_(q) alkylenegroup with q=2, 3 or 4, or a phenylene group, where the total of theindividual mole percentages is 100 mol %,where the molar ratio of (b1)to (b2) is chosen in the range from 0.4:1 to 1.5:1, (a2) from 0.1 to 5%by weight of a divinyl ether C1 and (a3) from 0 to 5 mol %, based oncomponent (b1) from the preparation of P1, of compound D with at leastthree groups capable of ester formation, (c2) 0.01-50% by weight, basedon (c1), of amino carboxylic acid B1where the amino carboxylic acid B1is selected from the group consisting of the natural amino acids,polyamides with a molecular weight not exceeding 18,000 g/mol, obtainedby polycondensation of a dicarboxylic acid with 4 to 6 carbon atoms anda diamine with 4 to 10 carbon atoms and compounds which are defined bythe formulae IIIa and IIIb ##STR17## where p is an integer from 1 to1500 and r is an integer from 1 to 4, and G is a radical which isselected from the group consisting of phenylene, --(CH₂)n--, where n isan integer from 1 to 12, --C(R²)H-- and --C(R²)HCH₂, where R² is methylor ethyl, and polyoxazolines with the repeating unit IV ##STR18## whereR³ is hydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl, and (c3) 0-5 mol %, based on the molar quantity ofcomponent (b1) used to prepare P1, of compound D,and, in a second step,reacting Q2 with (d1) 0.1-5% by weight, based on the polyetheresteramideQ2, of divinyl ether C1, and with (d2) 0-5 mol %, based on component(b1) from the preparation of P1, and polyetheresteramide Q2, of compoundD with at least three groups capable of ester formation.
 13. A processfor preparing the biodegradable polymers T2 with a molecular weight(M_(n)) in the range from 8000 to 80,000 g/mol, with a viscosity numberin the range from 30 to 450 g/ml (measured in o-dichlorobenzene/phenol(50/50 ratio by weight) at a concentration of 0.5% by weight polymer T2at 25° C.) and a melting point in the range from 50° to 255° C., whichcomprises, in a first step, preparing polyetheresteramide Q1 with amolecular weight (M_(n)) in the range from 6,000 to 80,000 g/mol aviscosity number in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide Q1 at 25° C.), and a melting point inthe range from 50° to 200° C., obtained by reacting a mixture of(a1)from 95 to 99.9% by weight polyetheresteramide P1 with a molecularweight (M_(n)) in the range from 5000 to 80,000 g/mol, a viscositynumber in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide P1 at 25° C.) and a melting point inthe range from 50° to 200° C., obtained by reacting a mixture consistingessentially of (b1) a mixture consisting essentially of (b11) 20-95 mol% adipic acid or ester-forming derivatives thereof or mixtures thereof,(b12) 5-80 mol % terephthalic acid or ester-forming derivatives thereofor mixtures thereof, and (b13) 0-5 mol % of a compound containingsulfonate groups, where 0-50 mol % of component (b11) can be replaced byat least one other aliphatic C₄ -C₁₀ - or cycloaliphatic C₅ -C₁₀-dicarboxylic acid or dinier fatty acid, and where 0-50 mol % ofcomponent (b12) can be replaced by another aromatic dicarboxylic acid,where the total of the individual mole percentages being 100 mol %, and(b2) a mixture of dihydroxy compounds composed of (b21) from 15 to 99.3mol % of a dihydroxy compound selected from the group consisting of C₂-C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22) from 0.2 to 85 mol% of a dihydroxy compound which contains ether functionalities and hasthe formula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof, (b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or anamino C₅ -C₁₀ -cycloalkanol (b24) from 0 to 50 mol % of a diamino-C₁ -C₈-alkane, (b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of the generalformula II ##STR19## where R¹ is a single bond, a (CH₂)_(q) alkylenegroup with q=2, 3 or 4, or a phenylene group, where the total of theindividual mole percentages is 100 mol %,where the molar ratio of (b1)to (b2) is chosen in the range from 0.4:1 to 1.5:1, (a2) from 0.1 to 5%by weight of a divinyl ether C1 and (a3) from 0 to 5 mol %, based oncomponent (b1) from the preparation of P1, of compound D, with at leastthree groups capable of ester formation, and, in a second step reactingQ1 with (e1) 0.01 to 50% by weight, based on polyetheresteramide Q1,amino carboxylic acid B1,where the amino carboxylic acid B1 is selectedfrom the group consisting of the natural amino acids, polyamides with amolecular weight not exceeding 18,000 g/mol, obtainable bypolycondensation of a dicarboxylic acid with 4 to 6 carbon atoms and adiamine with 4 to 10 carbon atoms and compounds which are defined by theformulae IIIa and IIIb ##STR20## where p is an integer from 1 to 1500and r is an integer from 1 to 4, and G is a radical which is selectedfrom the group consisting of phenylene, --(CH₂)_(n) --, where n is ainteger from 1 to 12, --C(R²)H-- and --C(R²) HCH₂, where R² is methyl orethyl,and polyoxazolines with the repeating unit IV ##STR21## where R³is hydrogen, C₁ C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl and (e2) 0-5 mol %, based on the molar quantity ofcomponent (b1) used to prepare polyetheresteramide Q1, of compound D.14. A process for preparing the biodegradable polymers T2, whichcomprises, in a first step, reacting(f1) polyetheresteramide P2 with amolecular weight (M_(n)) in the range from 5000 to 80,000 g/mol, aviscosity number in the range from 30 to 45 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide P2 at 25° C.) and a melting point inthe range from 50 to 255° C., obtained by reacting a mixture consistingessentially of (g1) a mixture consisting essentially of20-95 mol %adipic acid or ester-forming derivatives thereof or mixtures thereof,5-80 mol % terephthalic acid or ester-forming derivatives thereof ormixtures thereof, and 0-5 mol % of a compound which contains sulfonategroups, where the total of the individual mole percentages is 100 mol %,(g2) mixture (b2), consisting of dihydroxy compounds of(b21) from 15 to99.3 mol % of a dihydroxy compound selected from the group consisting ofC₂ -C₆ -alkanediols and C₅ -C₁₀ -cycloalkanediols, (b22) from 0.2 to 85mol % of a dihydroxy compound which contains ether functionalities andhas the formula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof, (b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or anamino-C₅ -C₁₀ -cycloalkanol and (b24) from 0 to 50 mol % of a diamino-C₁-C₈ -alkane, (b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of theformula II ##STR22## where R¹ is a single bond, a (CH₂)_(q) alkylenegroup with q=2, 3 or 4, or a phenylene group, where the total of theindividual mole percentages is 100 mol %,where the molar ratio of (g1)to (g2) is chosen in the range from 0.4:1 to 1,5:1, (g3) from 0.01 to40% by weight, based on component (g1), amino carboxylic acid B1wherethe amino carboxylic acid B1 is selected from the group consisting ofthe natural amino acids, polyamides with a molecular weight notexceeding 18,000 g/mol, obtained by polycondensation of a dicarboxylicacid with 4 to 6 carbon atoms and a diamine with 4 to 10 carbon atomsand compounds which are defined by the formulae IIIa and IIIb ##STR23##where p is an integer from 1 to 1500 and r is an integer from 1 to 4,and G is a radical which is selected from the group consisting ofphenylene, --(CH₂)_(n) --, where n is an integer from 1 to 12,--C(R²)H-- and --C(R²)HCH₂, where R² is methyl or ethyl, andpolyoxazolines with the repeating unit IV ##STR24## where R³ ishydrogen, C₁ -C₆ -alkyl, C₅ -C₈ -cycloalkyl, phenyl which isunsubstituted or substituted up to three times by C₁ -C₄ -alkyl groups,or tetrahydrofuryl, and (g4) from 0 to 5 mol %, based on component (g1),of compound D with at least three groups capable of ester formation,or(f2) a mixture consisting essentially of polyetheresteramide P1 with amolecular weight (M_(n)) in the range from 5000 to 80,000 g/mol, aviscosity number in the range from 30 to 450 g/ml (measured ino-dichlorobenzene/phenol (50/50 ratio by weight) at a concentration of0.5% by weight polyetheresteramide P1 at 25° C.) and a melting point inthe range from 50° to 200° C., obtained by reacting a mixture consistingessentially of (b1) a mixture consisting essentially of (b11) 20-95 mol% adipic acid or ester-forming derivatives thereof or mixtures thereof,(b12) 5-80 mol % terephthalic acid or ester-forming derivatives thereofor mixtures thereof, and (b13) 0-5 mol % of a compound containingsulfonate groups, where 0-50 mol % of component (b11) can be replaced byat least one other aliphatic C₄ -C₁₀ - or cycloaliphatic C₅ -C₁₀-dicarboxylic acid or dinier fatty acid, and where 0-50 mol % ofcomponent (b12) can be replaced byanother aromatic dicarboxylic acid,where the total of the individual mole percentages being 100 mol %,andwhere the molar ratio of (b1) to (b2) is chosen in the range from0.4:1 to 1.5:1, and 0.01 to 50% by weight, based on polyetheresteramideP1, of aminocarboxylic acid B1 or (f3) a mixture consisting essentiallyof polyetheresteramides P1 which differ from one another incompositionwith 0.1 to 5% by weight, based in the amount ofpolyetheresteramides used, of divinyl ether C1 and with 0 to 5 mol %,based on the respective molar quantities of component (g1) or component(b1) which were used to prepare the polyetheresteramides P2 used or themixtures (f2) or (f3), of compound D with at least three groups capableof ester formation.
 15. A process for the preparation of biodegradablethermoplastic molding compositions T4, comprising, in a first step,mixing polyetheresteramide Q1 with a molecular weight (M_(n)) in therange from 6000 to 80,000 g/mol, a viscosity number in the range from 30to 450 g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio byweight) at a concentration of 0.5% by weight polyetheresteramide Q1 at25° C.), and a melting point in the range from 50° to 200° C., obtainedby reacting a mixture of(a1) from 95 to 99.9% by weightpolyetheresteramide P1 with a molecular weight (M_(n)) in the range from5000 to 80,000 g/mol, a viscosity number in the range from 30 to 450g/ml (measured in o-dichlorobenzene/phenol (50/50 ratio by weight) at aconcentration of 0.5% by weight polyetheresteramide P1 at 25° C.) and amelting point in the range from 50° to 200° C., obtained by reacting amixture consisting essentially of (b1) a mixture consisting essentiallyof (b11) 20-95 mol % adipic acid or ester-forming derivatives thereof ormixtures thereof, and (b12) 5-80 mol % terephthalic acid orester-forming derivatives thereof or mixtures thereof, and (b13) 0-5 mol% of a compound containing sulfonate groups, where 0-50 mol % ofcomponent (b11) can be replaced by at least one other aliphatic C₄-C₁₀ - or cycloaliphatic C₅ -C₁₀ -dicarboxylic acid or dinier fattyacid, and where 0-50 mol % of component (b12) can be replaced by anotheraromatic dicarboxylic acid, where the total of the individual molepercentages being 100 mol %, and (b2) a mixture of dihydroxy compoundscomposed of (b21) from 15 to 99.3 mol % of a dihydroxy compound selectedfrom the group consisting of C₂ -C₆ -alkanediols and C₅ -C₁₀-cycloalkanediols, (b22) from 0.2 to 85 mol % of a dihydroxy compoundwhich contains ether functionalities and has the formula I

    HO-- (CH.sub.2).sub.n --O!.sub.m --H                       I

where n is 2, 3 or 4 and m is an integer from 2 to 250, or mixturesthereof, (b23) from 0.5 to 80 mol % of an amino-C₂ -C₁₂ -alkanol or anamino-C₅ -C₁₀ -cycloalkanol and (b24) from 0 to 50 mol % of a diamino-C₁-C₈ -alkane, (b25) from 0 to 50 mol % of a 2,2'-bisoxazoline of thegeneral formula II ##STR25## where R¹ is a single bond, a (CH₂)_(q)alkylene group with q=2, 3 or 4, or a phenylene group, where the totalof the individual mole percentages is 100 mol %,where the molar ratio of(b1) to (b2) is chosen in the range from 0.4:1 to 1.5:1, (a2) from 0.1to 5% by weight of a divinyl ether C1 and (a3) from 0 to 5 mol %, basedon component (b1) from the preparation of P1, of compound D with atleast three groups capable of ester formation,and in a second stepmixing from 99.5 to 0.5% by weight of polyetheresteramide Q1 with0.5-99.5% by weight of hydroxycarboxylic acid H1 of the general formulaVa or Vb ##STR26## where x is an integer from 1 to 1500 and y is aninteger from 1 to 4, and M is a radical which is selected from the groupconsisting of phenylene, --(CH₂)_(z) --, where z is an integer from 1 to5, --C(R²)H-- and --C(R²)HCH₂ where R² is methyl or ethyl.